Human activities significantly altered the nitrogen cycle , we saw how nitrogen
could be incorporated to our agricultural system.
From rarly 20th cen, our chemical advance allowed us to do what bacteria was
doing for us before , that is converting nitrogen into useable forms
This altered the landscape and how nitrogen was incorporated to the system
--> great growth in agriculture, fertilizers have high percentage of nitrogen
b/c it's needed for growth to happen
Nitrogen in the atmosphere will be doubled in 25 yrs, this is an enormous amount
Impact? Concept of Eutrophication, richness in the water body, an excessive
Many plants will grow, which will decompose and cause the problem creating
oxygen sucked up by decomposition process. Makes water less easy to clean up or
Smog, acid rain and formation of green house gases, would also be a factor other
than carbon dioxide.
Phosphorus cycle (another fertilizer)
•Big diff b/t this and nitrogen, phosphorus is not in our atmosphere nor can be
altered to be created
Yet still an imp. Element in our dna and atp (chemical energy).
Basic understanding of how phosphorus works through food chain is, we don't get it
from atmosphere instead, we find it in the land.
It's in the earth's systems. Phosphates move through the food chain
Organism eat plant -> organism eat other organism -> -> organism dies ->
phosphorus goes back into the land
= Organisms making an access to phosphate
b/c it's not in our atmosphere it's in a patchy distribution
There're areas that doesn't have so much phosphorous this is why plants grow
abundantly when it has phosphorus in fertilizer
When it's trapped in the lithosphere it won't move like nitrogen that's in the
atmosphere but will stay there
Once it ends up in ocean, seabed that's very deep that phosphorus will be tied up
So the cycle can take a very long geological time
Although having an abundance of phosphorus is a good thing, over-abundance
causes\ similar things as things caused by over abundance of nitrogen.